Rotating electric machines such as electric motors and generators typically include a stator and a rotor which rotates relative to the stator. Depending on the type of electrical machine (i.e. motor, generator, AC, DC, etc.), either the rotor or the stator includes electrically conductive windings. As these windings tend to become hot as a result of the current flowing therethrough, it is known to provide these windings with cooling means in the form of a fluid coolant fed through fluid-flow passages defined a body of the winding. Thus such cooling means act as a heat exchanger to exchange heat between the surrounding winding body and the coolant fluid flowing therethrough.
However small electric machines require very small-scale cooling channels to be formed, such as by machining, within the body of the windings. Such small cooling channels are difficult and expensive to manufacture. Accordingly, improvement is sought.